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+# Flang 11.0.0 (In-Progress) Release Notes
+
+> **warning**
+>
+> These are in-progress notes for the upcoming LLVM 11.0.0 release.
+> Release notes for previous releases can be found on [the Download
+> Page](https://releases.llvm.org/download.html).
+
+## Introduction
+
+This document contains the release notes for the Flang Fortran frontend,
+part of the LLVM Compiler Infrastructure, release 11.0.0. Here we
+describe the status of Flang in some detail, including major
+improvements from the previous release and new feature work. For the
+general LLVM release notes, see [the LLVM
+documentation](https://llvm.org/docs/ReleaseNotes.html). All LLVM
+releases may be downloaded from the [LLVM releases web
+site](https://llvm.org/releases/).
+
+Note that if you are reading this file from a Git checkout, this
+document applies to the *next* release, not the current one. To see the
+release notes for a specific release, please see the [releases
+page](https://llvm.org/releases/).
+
+## Known Issues
+
+These are issues that couldn't be fixed before the release. See the bug
+reports for the latest status.
+
+ *   ...
+
+## Introducing Flang
+
+Flang is LLVM's Fortran front end and is new for the LLVM 11 release.
+
+Flang is still a work in progress for this release and is included for
+experimentation and feedback.
+
+Flang is able to parse a comprehensive subset of the Fortran language
+and check it for correctness. Flang is not yet able to generate LLVM IR
+for the source code and thus is unable to compile a running binary.
+
+Flang is able to unparse the input source code into a canonical form and
+emit it to allow testing. Flang can also invoke an external Fortran
+compiler on this canonical input.
+
+Flang's parser has comprehensive support for:
+ * Fortran 2018
+ * OpenMP 4.5
+ * OpenACC 3.0
+
+Interested users are invited to try to compile their Fortran codes with
+flang in and report any issues in parsing or semantic checking in
+[bugzilla](https://bugs.llvm.org/enter_bug.cgi?product=flang).
+
+### Major missing features
+
+ * Flang is not supported on Windows platforms.
+
+## Using Flang
+
+Usage: `flang hello.f90 -o hello.bin`
+
+By default, Flang will parse the Fortran file `hello.f90` then unparse it to a
+canonical Fortran source file. Flang will then invoke an external
+Fortran compiler to compile this source file and link it, placing the
+resulting executable in `hello.bin`.
+
+To specify the external Fortran compiler, set the `F18_FC` environment
+variable to the name of the compiler binary and ensure that it is on your
+`PATH`. The default value for `F18_FC` is `gfortran`.
+
+When invoked with no source input, Flang will wait for input on stdin.
+When invoked in this way, Flang performs the same actions as if
+called with `-fdebug-measure-parse-tree -funparse` and does not invoke
+`F18_FC`.
+
+For a full list of options that Flang supports, run `flang --help`.
+
+## Additional Information
+
+Flang's documentation is located in the `flang/docs/` directory in the
+LLVM monorepo.
+
+If you have any questions or comments about Flang, please feel free to
+contact us via the [mailing
+list](https://lists.llvm.org/mailman/listinfo/flang-dev).